AirSay lets you write text in the air! Just enter your text and wave phone on an arc, like when you are greeting someone. Vibrations will help you with the right timing.
Looks great on honeycomb tablets as well!
Works best with short texts - see http://www.youtube.com/watch?v=CY6vjtElqkE for an example of AirSay in action.
Important changes:
1.5: New rendering engine - a bit smoother, handles pausing (no crashes when switching back to running AirSay)
1.4: Shiny new icon, text field is always visible (only history scrolls), improved keyboard handling (keyboard opens automatically)
1.3: Text history - show your previously used text without having to retype it.
Website and demo video:
http://www.mobreactor.com/airsay
Plans:
Orientation fix for landscape honeycomb tablets is on the way - it's simple to do in froyo, but a bit tricky to get right without losing compatibility with eclair (2.1).
